1. Field of the Disclosure
This disclosure relates to methods of forming electronic devices, and more particularly, to ion implanting regions having deep implant regions relative to adjacent shallow implant regions.
2. Description of the Related Art
Typically implant regions are formed through a series of processes, including for example masking, implanting, and possibly a thermal treatment process. Even more processing steps may be used to form implant regions of different junction depths, such as an implant region having a shallow junction region and a deep junction region relative to the shallow junction region. FIGS. 1-2 illustrate a known method of forming an implant region having different depths. In FIG. 1, a resist layer 103 is formed over a substrate 101. The resist layer 103 includes an opening 104 wherein the substrate 101 is exposed. During processing, ions are directed at the work surface including the resist layer 103 and the opening 104, such that the ions are implanted within the substrate 101 only in the portion of substrate underlying the opening 104 in the resist layer 103, thereby forming a implant region 107.
Referring to FIG. 2, after forming the implant region 107, the resist layer 103 can be removed and replaced with a different resist layer 109. The resist layer 109 has an opening 110 that is wider and overlying the implant region 107 and portions of the substrate 101. An ion implanting process can be completed to form a second implant region 113 in the portion of the substrate 101 underlying the opening 110. By comparison, the second implant region 113 has a shallower junction depth than the previously formed implant region 107 thereby forming a shallow junction region and a deep junction depth region. Thus, two separate resist layers 103 and 109 are used to form the implant regions 107 and 113.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.